ArghandaB, Afghanistan — Taliban militants destroyed bridges and planted mines in several villages they control outside southern Afghanistan's largest city in apparent preparation for battle, residents and officials said Tuesday.

More than 700 families – meaning perhaps 4,000 people or more – had fled the Arghandab district 10 miles northwest of Kandahar city, said Sardar Mohammad, a police officer manning a checkpoint on the east side of the Arghandab River. Police on Tuesday stopped and searched every person passing on the road.

On the west side of the river, hundreds of Taliban controlled around nine or 10 villages, Mr. Mohammad said.

The Taliban have long sought to control Arghandab and the good fighting positions its pomegranate and grape groves offer. From there, militants can cross the countryside's flat plains on a decent road network for probing attacks into Kandahar itself, in possible preparation for an assault on their former spiritual home.

The Afghan Army, which flew four planeloads of soldiers to Kandahar on Tuesday from the capital, Kabul, said 300 to 400 militants had gathered in Arghandab, many of them foreign fighters. The US-led coalition, however, said it conducted a patrol through the region "and found no evidence that militants control the area."

"Recent reports of militant control in the area appear to be unfounded," the coalition said in a statement.

Laity said 700 Afghan Army troops have moved from Kabul to Kandahar to deal with the Arghandab threat.

The Taliban assault Monday was the latest display of strength by the militants. The push into Arghandab district – a region the Soviet Army was never able to conquer – came three days after a coordinated Taliban attack on Kandahar's prison that freed 400 insurgent fighters.

Police and army soldiers increased security throughout Kandahar and enforced a 10 p.m. curfew.

A Taliban commander named Mullah Ahmedullah called an Associated Press reporter on Tuesday and said that about 400 Taliban moved into Arghandab from Khakrez, one district to the north. He said some of the militants released in Friday's prison break had joined the assault. "They told us, 'We want to fight until the death,' " Ahmedullah said. "We've occupied most of the area and it's a good place for fighting. Now we are waiting for the NATO and Afghan forces."

The hardline Taliban regime ousted from power in a 2001 US-led invasion of Afghanistan regarded Kandahar as its main stronghold, and its insurgent supporters are most active in the volatile south of the country.

The US and NATO have pleaded for additional troops over the last year and now have some 65,000 in the country. But the militants are still finding successes that the international alliance can't counter.

Arghandab lies just northwest of Kandahar city, and a tribal leader from the region warned that the militants could use the cover from Arghandab's orchards to mount an attack on Kandahar itself. NATO officials dismiss the idea that the Taliban can mount an attack on Kandahar.

One of the thousands of Afghans fleeing Arghandab said Tuesday that families were being forced out just as grape groves needed harvesting, meaning financial ruin for thousands. Haji Ibrahim Khan said Taliban fighters were moving through several Arghandab villages with weapons on their shoulders, planting mines, and destroying small bridges.

Two anti-Taliban leaders from Arghandab have died in the last year, weakening the region's defenses.

The assault Monday came one day after President Hamid Karzai angrily said he would send Afghan troops into Pakistan to hunt down Taliban leaders in response to the militants who cross into Afghanistan from Pakistan.